Method and apparatus for providing internet protocol datacasting(ipdc) service, and method and apparatus for processing ipdc service

ABSTRACT

Provided are a method and apparatus for providing an Internet Protocol Datacasting (IPDC) service. The IPDC service providing apparatus includes a data input unit generating an IP packet and signaling information of the IP packet; a packet generation control unit determining a type of an Internet Protocol Data Group (IPDG) packet that is to be generated by encapsulating the IP packet, on the basis of characteristics of the IPDC service; an IPDG packet generation unit generating an IPDG packet according to a data type of the IP packet, and generating an IPDG packet for the signaling information of the IP packet; a transfer stream packet generation unit generating the IPDG packet as a transfer stream packet; and a transfer unit transmitting the transfer stream packet. Accordingly, it is possible to provide an IPDC service while efficiently using a bandwidth, in a Digital Audio Broadcasting (DAB) system.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims priority from Korean Patent Application No.10-2007-0030050, filed on Mar. 27, 2007, in the Korean IntellectualProperty Office, and U.S. Provisional Patent Application No. 60/818,986,filed on Jul. 7, 2006, in the U.S. Patent and Trademark Office, thedisclosures of which are incorporated herein in their entireties byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Apparatuses and method consistent with the present invention relate to amethod and apparatus for providing an Internet Protocol Datacasting(IPDC) service, and more particularly, to a method and apparatus forproviding an IPDC service and a method and apparatus for processing theIPDC service, in a digital audio broadcast and a digital multimediabroadcast.

2. Description of the Related Art

Digital Audio Broadcasting (DAB) which provides a variety of additionaldata services, such as a weather service, a traffic service, anentertainment service, and an image service, as well as CD-levelhigh-quality audio services, using a latest audio encoding method havinga high compression rate is being serviced. Recently, Digital MultimediaBroadcasting (DMB) which is an improved type of the DMB is beingserviced.

Meanwhile, IPDC is a broadcast technique for transferring digitalcontent, such as games, video and audio files, and computer programs, toa plurality of users through a broadcast network. Since IPDC is abroadcast or a one-to-many distribution technology, the IPDC canefficiently transmit IP-based digital contents with high-cost efficiencyto many customers.

With development of the Digital Video Broadcasting-Handhelds (DVB-H)standard, IPDC-based services are being provided, but the DAB (ETSI EN300 401) has no standardized IPDC mechanism.

In the case of a DVB-Terrestrial/Handhelds (DVB-T/H), an MPEG-2 TS is alower layer transport mechanism, but in the DAB sub-channel of a MainService Channel (MSC) is a lower layer transport mechanism. When an IPdatagram is broadcast using a DVB-H protocol stack through a DABbroadcast system, bandwidth efficiency and processing may deterioratedue to overhead in Multi-Protocol Encapsulation (MPE) and MPEG-2 TSpacketization.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for efficientlyproviding an IPDC service using a new packetization method in a DAB orDMB system.

The present invention also provides a method and apparatus forprocessing an IPDC service which is provided using a new packetizationmethod.

According to an aspect of the present invention, there is provided anIPDC service providing method including: generating at least one IPpacket and signaling information of the at least one IP packet;determining a type of at least one Internet Protocol Data Group (IPDG)packet that is to be generated by encapsulating the at least one IPpacket, on the basis of characteristics of the IPDC service; generatingthe at least one IPDG packet according to the type of the at least oneIPDG packet, and generating an IPDG packet regarding the signalinginformation of the at least one IP packet; and generating the at leastone IPDG packet according to the type of the at least one IPDG packetand the IPDG packet regarding the signaling information of the at leastone IP packet, as at least one transfer stream packet; and transmittingthe at least one transfer stream packet.

According to another aspect of the present invention, there is providedan IPDC service providing apparatus including: a data input unitgenerating at least one Internet Protocol (IP) packet and signalinginformation of the at least one IP packet; a packet generation controlunit determining a type of at least one IPDG packet that is to begenerated by encapsulating the at least one IP packet, on the basis ofcharacteristics of the IPDC service; an IPDG packet generation unitgenerating the at least one IPDG packet according to the type of the atleast one IPDG packet, and generating an IPDG packet regarding thesignaling information of the at least one IP packet; a transfer streampacket generation unit generating the at least one IPDG packet accordingto the type of the at least one IPDG packet and the IPDG packetregarding the signaling information of the at least one IP packet, as atleast one transfer stream packet; and a transfer unit transmitting theat least one transfer stream packet.

According to another aspect of the present invention, there is providedan IPDC service processing method including: receiving at least onetransfer stream packet including at least one IPDG packet generated byencapsulating at least one IP packet; processing the at least onetransfer stream packet and generating the at least one IPDG packet;extracting the at least one IP packet or signaling information of the atleast one IP packet, from the at least one IPDG packet, using typeinformation indicating an IPDG packet type which is included in a headerof the at least one IPDG packet and determined on the basis ofcharacteristics of the IPDC service; and processing the at least one IPpacket and the signaling information of the at least one IP packet.

According to another aspect of the present invention, there is providedan IPDC service processing apparatus including: a receiver receiving atleast one transfer stream packet including at least one IPDG packetgenerated by encapsulating at least one IP packet; a transfer streampacket processing unit processing the at least one transfer streampacket and generating the at least one IPDG packet; an IPDG packetprocessing unit extracting the at least one Internet Protocol (IP)packet or signaling information of the at least one IP packet, from theat least one IPDG packet, using type information indicating an IPDGpacket type determined on the basis of characteristics of an IPDCservice included in a header of the at least one IPDG packet; and a dataprocessing unit processing the at least one IP packet or the signalinginformation of the at least one IP packet.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the attached drawings in which:

FIG. 1 is a view for explaining protocol stacks of a DAB service,according to an exemplary embodiment of the present invention;

FIG. 2 is a list of the types of an Internet Protocol Data Group (IPDG)Packet for an IPDC service, according to an exemplary embodiment of thepresent invention;

FIG. 3 is a view illustrating the structure of a normal IP packet;

FIG. 4 is a view illustrating a protocol stack of a highly-efficientIPDC service, according to an exemplary embodiment of the presentinvention;

FIG. 5 is a view illustrating the structure of an IPDG packet accordingto an exemplary embodiment of the present invention;

FIG. 6 is a view illustrating the structure of a Digital AudioBroadcast-Real-time Transport Protocol (DAB-RTP) type IPDG packetaccording to an exemplary embodiment of the present invention;

FIG. 7 is a view illustrating the structure of a compressed Real-timeTransport Protocol (RTP) type IPDG packet according to an exemplaryembodiment of the present invention;

FIG. 8 is a view illustrating the structure of a compressed IP type IPDGpacket according to an exemplary embodiment of the present invention;

FIG. 9 is a view illustrating the structure of a signaling type IPDGpacket according to an exemplary embodiment of the present invention;

FIG. 10 is a view illustrating the structure of a transfer stream packetinto which an IPDG packet is packetized, according to an exemplaryembodiment of the present invention;

FIGS. 11A and 11B are views for explaining a method of assigning ServiceIDentifiers (SIDs) to IPDG packets, according to an exemplary embodimentof the present invention;

FIGS. 12A through 12F are views illustrating a variety of structures ofa transfer stream packet into which at least one IPDG packet ispacketized, according to an exemplary embodiment of the presentinvention;

FIG. 13 is a view illustrating a user application data field for IPDCservice signaling through a DAB system, according to an exemplaryembodiment of the present invention;

FIG. 14 is a block diagram of an IPDC service providing apparatusaccording to an exemplary embodiment of the present invention;

FIG. 15 is a block diagram of an IPDC service processing apparatusaccording to an exemplary embodiment of the present invention;

FIG. 16 is a flowchart of an IPDC service providing method according toan exemplary embodiment of the present invention; and

FIG. 17 is a flowchart of an IPDC service processing method according toan exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the appended drawings.

FIG. 1 is a view for explaining a Digital Audio Broadcasting (DAB)service according to an exemplary embodiment of the present invention.

Referring to FIG. 1, it is assumed that a Digital VideoBroadcasting-Handheld (DVB-H) protocol stack 110 is used when an IPDC)service is provided through a Digital Audio Broadcasting (DAB) orDigital Multimedia Broadcasting (DMB) system. If the DVB-H protocolstack 110 is used, a bandwidth cannot be efficiently used to provide theIPDC service, as described above as a program of a related arttechnique.

In the DAB system, a protocol stack 120 is used to efficiently providethe IPDC service. As illustrated in the protocol stack 120, IP data isprocessed according to a highly-efficient-IPDC protocol of the IPDCservice, and transmitted through a Main Service Channel (MSC) of DAB.FIG. 1 shows a case where a DAB audio broadcast through Masking PatternAdapted Universal Sub-band Integrated Coding And Multiplexing (MUSICAM)of a MSC and multimedia objects are transmitted, and IP packets can betransmitted by IP tunneling through the MSC, wherein the MUSICAM is ahighly efficient audio coding process which can compress digital audiosignals to one of a number of possible encoding options in the range 8kbit/s to 384 kbit/s, at a sampling rate of 48 kHz. Also, DAB serviceinformation is transmitted through a Fast Information Channel (FIC).

FIG. 2 is a list of the types of an IPDG Packet for the IPDC service,according to an exemplary embodiment of the present invention.

FIG. 3 is a view illustrating the structure of a normal IP packet.

In the current exemplary embodiment, an IP packet or signalinginformation of the IP packet is encapsulated into an IPDG packet havinga variable length. A normal IP packet, as illustrated in FIG. 3,includes an IP header, a User Datagram Protocol (UDP) header, aReal-time Transport Protocol (RTP) header, and an RTP payload containingRTP data. According to an exemplary embodiment of the present invention,a normal IPDG packet for transmitting the normal IP packet asillustrated in FIG. 3 through a DAB or DMB network is generated. Also,according to an exemplary embodiment of the present invention, in orderto reduce a bandwidth when a normal IPDG packet is transmitted through abroadcast network, a different type of IPDG packet including only a partof IP packet data including an IP/UDP/RTP header and an RTP payload, orincluding a header of a compressed IP packet can be defined andtransmitted.

According to an exemplary embodiment of the present invention, the typeof IPDG packet is determined according to characteristics of an IPDCservice. The IPDG packet includes type information indicating a type ofthe IPDG packet. The characteristics of the IPDC service include atleast one among a bandwidth assigned to provide the IPDC service, acoverage range of the IPDC service, and a broadcast receiver type towhich the IPDC service can be provided.

The bandwidth assigned to provide the IPDC service may be used toprovide a single IPDC service or a plurality of IPDC services. Thecoverage range of the IPDC service can vary according to whether thepurpose of the IPDC service is to_simply receive data and provide it tousers, or to allow users to interactively use IP packets included in theIPDC service, such as communicating with other servers using IP packetsincluded in the IPDC service. Also, the type of IPDG packet can bedetermined in consideration of a function of a broadcast receiverterminal which will receive the IPDC service, for example, inconsideration of whether or not a broadcast receiver terminal which willreceive the IPDC service can process the IP packet.

Referring to FIG. 2, the types of the IPDG packet include a normal type(type information: “000”), a DAB-RTP type (type information: “001”), acompressed RTP type (type information: “010”), and a compressed IP type(type information: “011”). The normal type is a packet type fortransmitting an IP packet having a normal IP/UDP/RTP header. The DAB-RTPtype is a packet type for transmitting an RTP payload having noIP/UDP/RTP header. The compressed RTP type is a packet type fortransmitting an RTP payload having a compressed IP/UDP/RTP header. Thecompressed IP type is a packet type for transmitting a compressed IPpacket subjected to header compression.

Also, another type of the IPDG packet includes a DAB-IPDC signaling type(type information: “100”) for transmitting signaling information of anIP packet. The signaling information of the IP packet includes settinginformation, etc., for system initialization of a device which receivesan IPDC service. The DAB-IPDC signaling type will be described laterwith reference to Tables 1 and 2.

FIG. 4 is a view illustrating a protocol stack of a highly efficientIPDC service, according to an exemplary embodiment of the presentinvention.

As illustrated in FIG. 4, in order to provide the IPDC service, an IPDGpacket is generated by encapsulating signaling information and IP packetdata into an IPDG. Then, the IPDG packet is packetized into a transferstream packet (also referred to as a DAB-TS packet), and the transferstream packet is encoded by an outer coder and then transmitted. Thesize of the transfer stream packet is 188 bytes. The outer coderperforms convolution interleaving and RS coding on the transfer streampacket. Thus, bits for error correction coding (ECC) are added to the188 bytes of the transfer stream packet, so that the size of thetransfer stream packet is a total of 204 bytes.

FIG. 5 is a view illustrating the structure of an IPDG packet accordingto an exemplary embodiment of the present invention.

The IPDG packet basically includes an IPDG type field indicating an IPDGtype, a header field which is configured according to the IPDG type, anextension field configured according to the IPDG type, and a payload inwhich data according to the IPDG type is included.

A normal type IPDG packet will be described with reference to FIG. 5,below.

3 bits of an IPDG type field include information regarding the type ofpayload included in the IPDG packet. In the case of the normal type IPDGpacket, an IPDG type value included in the IPDG type field can be set to“000”. 1 bit of a CRC flag field represents whether a CRC flag is used.4 bits of an EH_SIZ field represent the size of a header which isextended in units of bytes. 16 bits of a length field represent thelength of data which is represented in units of bytes. In the currentexemplary embodiment, an extended header field EH_SIZE*8 represents anextended header of the IPDG packet. In the case of the normal type IPDGpacket, an IP/UDP/RTP header is included in the extended header field. Adata field DATA (variable) represents a payload of the IPDG packet. 16bits of a CRC field represent a CRC value of the IPDG packet part whichprecedes the CRC field. Meanwhile, a single normal IP packet or aplurality of successive IP packets can be encapsulated using the normaltype IPDG header.

FIG. 6 is a view illustrating the structure of a DAB-RTP type IPDGpacket according to an exemplary embodiment of the present invention.

As illustrated in FIG. 6, in the DAB-RTP type IPDG packet, 3 bits “001”of an IPDG type value represent that DAB-RTP type data is included in apayload. A time stamp of a time stamp field (32 bits) corresponds to atime stamp of an RTP header of an original IPDG packet. Also, a sequencenumber of a sequence number field (8 bits) corresponds to a sequencenumber of the RTP header of the original RTP packet. The time stampfield and the sequence number field correspond to the extended headerfield illustrated in FIG. 5.

The DAB-RTP type IPDG packet is obtained by encapsulating only an RTPpayload, in order to efficiently use a bandwidth of a DAB-based IPDCservice. The DAB-RTP type IPDG packet transmits RTP data and informationrequired to process an RTP packet. Here, the information required toprocess the RTP packet corresponds to the time stamp and sequence numbercontained in the RTP header of the IPDG packet.

The time stamp is used for synchronization of media data included in theRTP payload. The sequence number is used to check fragmentation of theRTP payload having the time stamp. The time stamp and sequence numberbecome a criterion for synchronization for the RTP payload.

When a DAB-IPDC broadcast receiver has no TCP/IP socket, that is, when aDAB-IPDC broadcast receiver cannot process IP packets as it does nothave a function of parsing IP/UDP headers, the DAB-IPDC broadcastreceiver cannot process IPDG packets including normal IP packets.However, the DAB-RTP type IPDG packet according to the current exemplaryembodiment can be processed by a DAB-IPDC broadcast receiver without aTCP/IP socket.

The other header information, such as an IP header, a UDP header, and anRTP header, can be generated by using a variety of devices. Essentialinformation includes an IP address, a port number, a time stamp, and asequence number. The essential information can be provided by adifferent path, for example, by a Fast Information Channel (FIC) or aSession Description Protocol (SDP).

FIG. 7 is a view illustrating the structure of a compressed RTP typeIPDG packet according to an exemplary embodiment of the presentinvention.

In FIG. 7, 3 bits “010” of an IPDG type value indicate that compressedRTP type data is included in a payload. If a broadcast receiver includesa high-performance CPU based on an IP terminal, the broadcast receivercan use a compressed RTP type packet having a compressed IP/UDP/RTPheader, as illustrated in FIG. 7.

In FIG. 7, a time stamp of a time stamp field (32 bits) corresponds to atime stamp of an RTP header of the original RTP packet, and a sequencenumber of a sequence number field (8 bits) corresponds to a sequencenumber of the RTP header of the original RTP packet. An RTP payloadpointer value of a pointer field (8 bits) indicates the location of astart byte of an RTP payload which follows a compressed IP/UDP/RTPheader in the data field.

When a broadcast receiver has no TCP/IP socket, the broadcast receivercannot process an IP/UDP header including a compressed IP/UDP/RTPheader. However, if a time stamp and a sequence number are included in aspecific field which precedes the compressed IP/UDP/RTP header, thebroadcast receiver can process the corresponding RTP payload even thoughthe broadcast receiver cannot decompress the compressed IP/UDP/RTPheader.

In the case of the broadcast receiver without the TCP/IP socket, an RTPpayload pointer field as well as a time stamp field and a sequencenumber field are used. Since a time stamp and sequence number provide anRTP payload pointer to a broadcast receiver, the broadcast receiver canprocess RTP type IPDG data having a compressed IP/UDP/RTP header evenwhen the broadcast receiver has no TCP/IP socket.

FIG. 8 is a view illustrating the structure of a compressed IP type IPDGpacket according to an exemplary embodiment of the present invention.

In FIG. 8, 3 bits “011” of an IPDG type value represent that compresseddata is included in a payload of the IPDG packet. When a broadcastreceiver based on an IP terminal includes a high-performance CPU so thatthe broadcast receiver can decompress a compressed header of an IPpacket, as illustrated in FIG. 8, a compressed IP type IPDG packetobtained by compressing a header of an IP packet can be used. Althoughthe compressed IP type IPDG packet requires a high-performance broadcastreceiver, the compressed IP type IPDG packet can provide an IPDC serviceusing a narrowest bandwidth compared to bandwidths required by differentIPDG packet types.

In the case of the compression type IPDG packet, compression type IPDGdata having a compressed IP/UDP/RTP header cannot be processed by abroadcast receiver without a TCP/IP socket function. Accordingly, thecompression IP type IPDG packet will be used selectively in specificcases.

FIG. 9 is a view illustrating the structure of a signaling type IPDGpacket according to an exemplary embodiment of the present invention.

In FIG. 9, 3 bits “100” of an IPDG type value represent that signalingtype data is included in a payload of the IPDG packet. Signaling datafor a DAB-IPDC service is encapsulated into a signaling type IPDGpacket, as illustrated in FIG. 9.

In FIG. 9, 8 bits of a version number field include a value whichrepresents a current version of an IPDC service.

By using the version number field, it is possible to represent whetherthe current version of the IPDC service changes. The IPDC serviceincludes a primary IPDC service and a complete IPDC service according toan exemplary embodiment of the present invention. The primary IPDCservice is a primary service of the IPDC service, and is defined by anIPDC-PAT (Internet Protocol DataCasting-Primary Service AnnouncementTable). The complete IPDC service is the remaining service whichexcludes the primary IPDC service from the IPDC service, and is definedby an IPDC-CAT (Internet Protocol DataCasting-Complete serviceAnnouncement Table). The two tables IPDC-PAT and IPDC-CAT aretransmitted according to a signaling type of an IPDG packet.

TABLE 1 IPDC-PAT Syntax NO. of bits Restrictions IPDC-PAT( ) { DAB_Bearer_Descriptor( ) N  SDP_Descriptor( ) M  CRC32 32 }

It describes how the IP packet and the SID are related and thisrelationship is reflected in the level of a DAB-IP bearer.“SDP_Descriptor( )” includes compressed SDP information of a primaryIPDC service. For high-speed access, “SDP_Descriptor( )” is included inthe IDPC-PAT.

TABLE 2 IPDC-CAT Syntax NO. of bits Restrictions IPDC-PAT( ) ; {  Asunit of Service L  {   DAB_Bearer_Descriptor( ) N   SDP_Descriptor( ) M }  CRC32 32 }

In Table 2, the use of “SDP_Descriptor( )” depends on the validity of anElectronic Service Guide (ESG) in an IPDC service.

FIG. 10 is a view illustrating the structure of a transfer stream packetinto which an IPDG packet is packetized, according to an exemplaryembodiment of the present invention.

An IPDG packet is subjected to time-division multiplexing, thereby beingpacketized into a transfer stream packet. The size of the transferstream packet is 188 bytes so that a related art error correction methodsuch as DVB-forward error correction (FEC) of a lower layer can beapplied to the transfer stream packet. A first byte of the transferstream packet is a synchronization byte having a value 0x47.

A header of the transfer stream packet includes a pointer flag, a sub-TSflag, an SID extended flag, and an SID extended field. 1 bit of thepointer flag represents whether a pointer field is used. 1 bit of thesub-TS flag represents whether a sub-TS header is used following a startbyte of data represented by a pointer value. The sub-TS flag means theconfiguration including the transfer stream packet header and a nextIPDG packet when two or more IPDG packets are included in the transferstream packet and a transfer stream packet header for the next IPDGpacket exists in the transfer stream packet.

1 bit of the SID extended flag represents whether 8 bits of the SIDextended field are used. The SID extended field may be an empty fieldwhich can be used later. However, the SID extended field is not used fora packet for IPDC signaling.

The SID represents a service ID assigned to the IPDG packet whichprovides an IPDC service.

The same SID can be assigned to all IPDG packets which provide the sameservice, or different SIDs can be respectively assigned to respectiveIPDG packets. The operation will be described below with reference toFIGS. 11A and 11B.

8 bits of a pointer field indicate the location of bytes of anencapsulated next IPDG packet.

FIGS. 11A and 11B are views for explaining a method of assigning ServiceIDentifiers (SIDs) to IPDC packets, according to an exemplary embodimentof the present invention.

As illustrated in FIG. 11A, an IPDC service has a plurality of mediapackets (audio and video IP packets), each of which has its own SID. InFIG. 11A, all IPDG packets for transmitting media data have the sameSID.

In the case of normal type IPDG packets, it is recommended that the sameSID is assigned to IPDG packets transmitting different media data. An IPheader of each IP packet includes a length field to identify the IPpacket, and an RTP header of each IP packet includes a media data typefield to identify a media data type of the IP packet.

However, if the IPDG packets are not normal type IPDG packets, differentSIDs are respectively assigned to respective IPDG packets of differentmedia data. The reason for this is because an IPDG packet, which is nota normal type, is transmitted in the state that its IP header iscompressed or omitted.

FIGS. 12A through 12F are views illustrating a variety of structures ofa transfer stream packet into which at least one IPDG packet ispacketized, according to an exemplary embodiment of the presentinvention.

FIG. 12A illustrates a transfer frame packet into which an IPDG packetis packetized. Referring to FIG. 12A, the size of the transfer framepacket is 188 bytes, and includes a synchronization field Sync, a DAB-TSheader, and data.

The IPDG packet has a variable length, and is divided and packetizedinto a plurality of transfer frame packets, wherein the size of eachtransfer frame packet is 188 bytes.

When a first segment of the IPDG packet is packetized into a DAB-TS, asillustrated in FIG. 12B, since a pointer value of a pointer fieldlocated in a selective header of the transfer stream packet asillustrated in FIG. 11 is “0”, the first segment of the IPDG packet isloaded following the pointer field.

When an intermediate segment of the IPDG packet is packetized into atransfer stream packet, as illustrated in FIG. 12C, a pointer flag valueincluded in the DAB-TS header of the transfer stream packet is “0”,which means that no pointer field exists and IPDG packet data is loadedfollowing the DAB-TS header.

When a final segment of the IPDG packet is packetized into a transferstream packet, as illustrated in FIGS. 12D through 12F, the transferstream packet can be of three types. In FIGS. 12D through 12F, IPDG(t)represents a current IPDG packet and IPDG(t+1) represents a next IPDGpacket.

First, as illustrated in FIG. 12D, if a next IPDG packet IPDG(t+1) towhich the same SID as that assigned to the current IPDG packet IPDG(t)is assigned is added to the current IPDG packet IPDG(t), a pointer flagof a header of the transfer stream packet is set to “1”, and M bytes areassigned to a pointer field of the header. Accordingly, the M bytes ofthe pointer field represent that the next IPDG packet IPDG(t+1) to whichthe same SID is assigned is loaded following the M bytes of the pointerfield.

Second, as illustrated in FIG. 12E, if a next IPDG packet IPDG(t+1) towhich an SID different from that assigned to a current IPDG packetIPDG(t) is assigned is added to the current IPDG packet IPDG(t), apointer flag is set to “1”, a sub-TS flag is set to “1”, and M bytes areassigned to a pointer field, in a header of the corresponding transferstream packet.

In a header of a sub-TS, that is, in a DAB-TS header before the nextIPDG packet IPDG(t+1), a pointer flag is set to “0”, a sub-TS flag isset to “0”, and a new SID is assigned to an SID field.

Third, as illustrated in FIG. 12F, if no next IPDG packet exists or if anew transfer frame packet is used to improve error resistance, a pointerflag is set to “1”, a sub-TS flag is set to “1”, and M bytes areassigned to a pointer field, in a header of the corresponding transferframe packet. In a header of a sub-TS of the transfer frame packet, apointer flag is set to “0”, a sub-TS flag is set to “0”, and “0” isassigned to an SID field. An SID value included in the header of thesub-TS is “0”, which indicates that stuffing data is included in thesub-TS.

FIG. 13 is a view illustrating a user application data field for IPDCservice signaling through a DAB system, according to an exemplaryembodiment of the present invention.

In order to provide an IPDC service through a broadcast network, it isnecessary to define detailed information of the IPDC service andannounce the IPDC service. In order to represent that an IPDG service isprovided through a DAB data channel, a user application type FIG. 0/13can be used. In the DAB system, an IPDC service can include a primaryIPDC service that is to be processed in priority order and a completeIPDC service. The user application data field transfers three 1-bytefields.

The first byte of the 1-byte fields transfers a primary IpdcSid, thesecond byte of the 1-byte fields transfers a complete IpdcSid, and thethird byte of the 1-byte fields transfers EsgSid. A broadcast receivercan ignore user application data following EsgSid. If an SID of ESG is“0”, IPDC-CAT has the “SDP_Descriptor” of each IPDC service.

The primary IPDC service can be accessed by a broadcast receiver, in thefollowing way. If a supply voltage is applied to the broadcast receiverand booting and RF tuning are complete, FIC is processed and SIDs ofIPDC-PAT and IPDC-CAT are found. Then, the broadcast receiver processesIPDC-PAT corresponding to the SID. After processing the IPDC-PAT, thebroadcast receiver processes SDP information from the “SDP_Descriptor”.Then, the broadcast receiver processes a transfer stream packet DAB-TSof an SID corresponding to “DAB_Bearer_Descriptor”. Finally, thebroadcast receiver processes each media IP packet by the correspondingDAB-IPDC application.

The complete IPDC service can be accessed by a broadcast receiver, inthe following way.

The broadcast receiver processes IPDC-CAT corresponding to an SID ofIPDC-CAT. After processing the IPDC-CAT, if “SDP_Descriptor” is valid,the broadcast receiver processes SDP information from the“SDP_Descriptor”. Then, the broadcast receiver processes a transferstream packet of an SID corresponding to “DAB_Bearer_Descriptor”.Finally, the broadcast receiver processes each media IP packet of anIPDG according to a user's selection.

If an SID of ESG (or the “SDP_Descriptor” of the IPDC-CAT) is not valid,the broadcast receiver processes a DAB-TS of an SID corresponding to the“DAB_Bearer_Descriptor”. Then, the broadcast receiver processes atransfer stream packet corresponding to ESG (Electronic Service Guide).After processing the IP packet by using FLUTE (File Delivery overUnidirectional Transport), the broadcast receiver processes a DAB-TScorresponding to ESG, and processes the ESG by using an ESG application.Thereafter, the user can select an IPDC service in the ESG. After theIPDC service is selected by the user, the broadcast receiver processeseach media IP packet of the IPDG. An IPDC service signaling methodthrough a DAB system can be implemented by different methods other thanthe methods as described above.

FIG. 14 is a block diagram of an IPDC service providing apparatusaccording to an exemplary embodiment of the present invention. The IPDCservice providing apparatus, which provides an IPDC service through abroadcast network, includes a data input unit 1410, a packet generatingcontroller 1420, an IPDG packet generator 1430, a transfer stream packetgenerating unit 1440, and a transfer unit 1450.

The data input unit 1410 generates an IP packet and signalinginformation of the IP packet. The data input unit 1410 can include anIPDC signaling packet generator 1412 and an IP data packet input unit1414. The IPDC data packet input unit 1414 receives the IP packet andtransfers the IP packet to the IPDG packet generating unit 1430. TheIPDC signaling packet generator 1412 transfers a packet including thesignaling information of the IP packet to the IPDG packet generatingunit 1430.

The packet generating controller 1420 encapsulates the IP packet on thebasis of the characteristics of an IPDC service, to generate an IPDGpacket, and determines the type of IPDG packet. The characteristics ofthe IPDC service include at least one service characteristic, such as abandwidth assigned to provide the IPDC service, a coverage range of theIPDC service, a broadcast receiver type to which the IPDC service willbe provided, etc. The packet generating controller 1420 can determinethe type of IPDG packet on the basis of at least one among the bandwidthassigned to provide the IPDC service, the coverage range of the IPDCservice, and the broadcast receiver type to which the IPDC service willbe provided. The packet control generating unit 1420, as described abovewith reference to FIG. 2, generates an IPDG packet corresponding to atype among a normal type, a DAB-RTP type, a compression RTP type, and acompression IP type. The normal type is used to transmit a normal IPpacket having IP, UDP and RTP headers. The DAB-RTP type is used totransmit RTP data and information required to process an RTP packet. Thecompression RTP type is used_to transmit information required to processan RTP packet, compressed IP, UDP, and RTP headers, and RTP data. Theinformation required to process the RTP packet is stored in an RTPheader of the IP packet, and includes a time stamp and a sequencenumber. The compressed IP type is used to transmit compressed IP, UDP,and RTP headers and RTP data.

A compressed RTP type of an IPDG packet includes a pointer field forrepresenting the location of an RTP payload so that a broadcast receiverwhich cannot process IP packets can access the RTP payload.

The packet control generating unit 1420 determines the type of IPDGpacket as the DAB-RTP type, for an IPDC service which provides only RTPpayload data. Also, the packet control generating unit 1420 determinesthe type of IPDG packet as the compression RTP type, for an IPDC servicewhich requires header information of an IP packet. Also, the packetcontrol generating unit 1420 determines the type of IPDG packet as thecompressed IP type, when the IPDG packet is transmitted to a broadcastreceiver for receiving an IPDC service which can process a header of acompressed IP packet while reducing a bandwidth compared to the normaltype, the DAB-RTP type, or the compression RTP type.

The IPDG packet generating unit 1430 generates the IPDG packet asillustrated in FIGS. 5 through 9, according to the IPDG type determinedby the packet control generating unit 1420. Also, the IPDG packetgenerating unit 1430 generates an IPDG packet regarding signalinginformation of the IP packet.

The IPDG packet generating unit 1430 can include an IPDC PAT IPDG packetgenerator 1431, an IPDC-CAT IPDG packet generator 1433, a normal typeIPDG packet generator 1432, a DAB-RTP type IPDG packet generator 1434, acompression RTP type IPDG packet generator 1436, and a compression IPtype IPDG packet generator 1438. The DAB-RTP type IPDG packet generator1434 can include a DAB-RTP type IPDG packet generator 1434, acompression RTP type IPDG packet generator 1436, and a compression IPtype IPDG packet generator 1438. The IPDC PAT IPDG packet generator 1431generates an IPDG packet including IPDC-PAT information, and theIPDC-CAT IPDG packet generator 1433 generates an IPDG packet includingIPDC-CAT information. The normal type IPDG packet generator 1432generates a normal type IPDG packet, the DAB-RTP type IPDG packetgenerator 1434 generates a DAB-RTP type IPDG packet, the compression RTPtype IPDG packet generator 1436 generates a compression RTP type IPDGpacket, and the compression IP type IPDG packet generator 1438 generatesa compression IP type IPDG packet.

The transfer stream packet generating unit 1440 packetizes the IPDGpacket as a transfer stream packet. The transfer stream packet caninclude at least one IPDG packet. The transfer stream packet generatingunit 1440 generates a transport stream packet having a size of 188bytes.

If IPDG packets of at least one different piece of multimedia data whichis transferred using transfer stream packets are normal type IPDGpackets when the same IPDC service is provided, the transfer streampacket generating unit 1440 assigns the same service identifier SID tothe IPDG packets. However, if IPDG packets of at least one differentpiece of multimedia data which is transferred using transfer streampackets are not normal type IPDG packets, different service identifiersSIDs are respectively assigned to the respective IPDG packets.

Also, if an IPDG packet is divided into a plurality of transfer streampackets, the transfer stream packet generating unit 1440 can representwhich part of data of the entire IPDG packet is transmitted through atransfer stream packet, using a pointer field indicating a location of anext IPDG packet or a location of a header of a transfer stream packetfor the next IPDG packet, which are contained in a header of thetransfer stream packet. Here, the transfer stream packet generating unit1440 generates the transfer stream packets in such a manner that atransfer stream packet for transferring a first segment of the IPDGpacket includes a pointer field having a value “0” in a header, atransfer stream packet for transferring an intermediate segment of theIPDG packet does not include a pointer field (a pointer flag=0) in aheader, and a transfer stream packet for transferring a final segment ofthe IPDG packet includes a pointer field having predetermined bytes of avalue in a header.

Also, when the transfer stream packet for transferring the final segmentof the IPDG packet is generated, the transfer stream packet generatingunit 1440 can generate the transfer stream packet as one of thefollowing three types.

If the same service identifier SID is assigned to IPDG packets of atleast one different piece of multimedia data, the transfer stream packetgenerating unit 1440 generates a transfer stream packet including one ormore successive IPDG packets. Also, if different service identifiersSIDs are assigned to an IPDG packet of at least one different piece ofmultimedia data, the transfer stream packet generating unit 1440generates a transfer stream packet including an IPDG packet to which anew service identifier SID is assigned after a final segment of theprevious IPDG packet. Also, if no different IPDG packet is included in atransfer stream packet, the transfer stream packet generating unit 1440generates a transfer stream packet including stuffing data following afinal segment of an IPDG packet.

The transfer unit 1450 includes an error resistant encoder 1452 and achannel encoder 1454. The error resistant encoder 1452 performs errorresistant coding, such as the addition of parity bits, the addition oferror resistant codes, etc., on 188 bytes of a transfer stream packet sothat the transfer stream packet has error resistance. The channelencoder 1454 performs channel encoding, such as OFDM or VSB, on theresultant transfer stream packet.

FIG. 15 is a block diagram of an IPDC service processing apparatusaccording to an exemplary embodiment of the present invention. The IPDCservice processing apparatus is a broadcast receiver for receiving anIPDC service through a broadcast network and processing the IPDCservice, and includes a receiver 1510, a transfer stream packetprocessor 1520, an IPDG packet processor 1530, and a data processor1540.

The receiver 1510 receives a transfer stream packet including an IPDGpacket obtained by encapsulating an IP packet. The receiver 1510 caninclude a channel decoder 1512 and an error resistant packet decoder1514. The channel decoder 1512 channel-decodes data channel-encoded byan IPDC service providing apparatus, according to a predeterminedmethod. The error resistant packet decoder 1514 decodes data encoded forerror resistance and generates a 188 byte transfer stream packet.

The transfer stream packet processor 1520 processes the transfer streampacket and extracts an IPDG packet from the transfer stream packet. Ifan IPDG packet is divided into a plurality of transfer stream packetsand the transfer stream packets are transferred, a process ofreassembling the IPDG packet is performed.

The IPDG packet processor 1530 extracts an IP packet from the IPDGpacket, using type information indicating an IPDG type which isdetermined on the basis of the characteristics of the IPDC serviceincluded in the header of the IPDG packet, and extracts signalinginformation from the IP packet. The IPDG packet processor 1530 caninclude an IPDG packet decoder 1532, an IPDG signaling packet extractor1534, and an IP data packet output unit 1536.

The IPDG packet decoder 1532 divides the IP packet into an IP signalingpacket and an IPDG packet for transmitting IP packet data, according tothe type information. The IPDG signaling packet extractor 1534 extractsthe IP signaling packet from the IP packet, and transfers signalinginformation of a primary service and a complete service to the IPDCsignaling data processor 1542. The IP data packet output unit 1536transfers the IP packet to an IP data processor 1544 which processes thesame SID.

The data processor 1540 includes an IPDG signaling packet data processor1542 and the IP data processor 1544, and processes IP packets orsignaling information of the IP packets. Here, an IP packet is based onthe type of an IPDG packet. The term “an IP packet” includes data whichis encapsulated into an IPDG packet, as well as a normal IP packet. Datawhich is processed by the IP data processor 1544 depends on the type ofIPDG packet that is to be transmitted, and can vary depending on whetheran IPDC service processor is able to process IP packets or headers of IPpackets.

If a normal type IPDG packet is received, the IP data packet output unit1536 outputs a normal IP packet, and the IP data processor 1544processes the normal IP packet according to a general IP packetprocessing method.

If the type of an IPDG packet including an IP packet is a DAB-RTP typefor transmitting RTP data and information required to process an RTPpacket, the IP data processor 1544 accesses RTP data included in apayload of the IPDG packet, using the information required to processthe RTP packet, and transfers the RTP data to the data processor 1540.The IP data processor 1542 of the data processing unit 1540 processesthe RTP data. If IP and UDP headers are transferred through a differentpath and the IP packet data processor 1544 has a TCP/IP socket, a methodof processing normal IP packets can be used.

If the IPDG packet is a compression RTP type, and has a function forrestoring IP, UDP, and RTP headers, the IP data processor 1544 restorescompressed IP, UDP, and RTP headers in order to access RTP data, andprocesses the RTP data. If the IP data processor 1544 does not have thefunction for restoring IP, UDP, and RTP headers, the IP data processor1544 accesses RTP data included in a payload of an IPDG packet by usinginformation required to process an RTP packet, and processes the RTPdata.

If the type of IPDG packet is a compressed IP type for transmittingcompressed IP, UDP, and RTP headers and RTP data, the IP data processor1544 restores compressed IP, UDP, and RTP headers to access RTP data,and processes the RTP data.

The IPDG signaling packet data processor 1542 of the data processor 1540processes primary signaling information for a primary service of an IPDCservice, and complete signaling information for the remaining IPDCservice.

The data processor 1540 processes at least one IP packet included in atleast one IPDG packet having the same service identifier SID foridentifying an IPDC service included in a header of a transfer streampacket, and provides the IPDC service.

FIG. 16 is a flowchart of an IPDC service providing method according toan exemplary embodiment of the present invention.

In operation S1610, an IP packet and signaling information of the IPpacket are generated.

In operation S1620, the type of an IPDG packet that is to be generatedby encapsulating the IP packet is determined, on the basis of thecharacteristics of an IPDC service. In operation S1620, if the IPDCservice can be provided using only data of an RTP payload, the type ofIPDG packet that is to be generated is determined as a DAB-RTP type. Ifthe IPDC service requires header information of the IP packet, the typeof IPDG packet that is to be generated is determined as a compressed RTPtype. If the IPDC service is provided to a broadcast receiver forreceiving an IPDC service which can process the IP packet while reducinga bandwidth, compared to the normal type, the DAB-RTP type, or thecompressed RTP type, the type of IPDG packet that is to be generated isdetermined as a compressed IP type.

In operation S1630, the IPDG packet is generated according to the typeof IPDG packet, and an IPDG packet is generated using signalinginformation of the IP packet

In operation S1640, the IPDG packets are generated as a transfer streampacket.

In operation S1650, the transfer stream packet is transmitted.

FIG. 17 is a flowchart of an IPDC service processing method according toan exemplary embodiment of the present invention.

In operation S1710, a transfer stream packet including an IPDG packetgenerated by encapsulating an IP packet is received.

In operation S1720, the transfer stream packet is processed, so that theIPDG packet is generated.

In operation S1730, an IP packet or signaling information of the IPpacket is extracted from the IPDG packet, using type informationindicating an IPDG type determined on the basis of the characteristicsof an IPDC service included in a header of the IPDG packet.

In operation S1740, the IP packet or the signaling information of the IPpacket is processed.

The present invention can also be embodied as computer readable codes ona computer readable recording medium. The computer readable recordingmedium is any data storage device that can store data which can bethereafter read by a computer system. Examples of the computer readablerecording medium include read-only memory (ROM), random-access memory(RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storagedevices, and other embodiments. The computer readable recording mediumcan also be distributed over network coupled computer systems so thatthe computer readable code is stored and executed in a distributedfashion.

According to the present invention, by selectively generating andtransmitting IP packet data, as a normal type IPDG packet, a DAB-RTPtype IPDG packet, a compression RTP type, or a compression IP type IPDGpacket, according to the characteristics of an IPDC service, such as abandwidth assigned for the IPDC service, a purpose of the IPDC service,or a broadcast receiver type for receiving the IPDC service, it ispossible to efficiently use a bandwidth and provide an IPDC service in aDAB (or DMB) system.

Also, according to the present invention, by providing a DAB-RTP typeIPDG packet and a compression RTP type IPDG packet, it is possible toprovide an IPDC service to a broadcast receiver without a TCP/IP socket.

Also, according to the present invention, by providing a DAB-RTP typeIPDG packet and a compression RTP type IPDG packet, an IPDC service canbe provided to broadcast receivers with or without a TCP/IP socket.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1. An Internet Protocol Datacasting (IPDC) service providing methodcomprising: generating at least one IP packet and signaling informationof the at least one IP packet; determining a type of at least oneInternet Protocol Data Group (IPDG) packet to be generated byencapsulating the at least one IP packet, based on characteristics ofthe IPDC service; generating the at least one IPDG packet according tothe type of the at least one IPDG packet; generating an IPDG packetregarding the signaling information of the at least one IP packet;generating at least one transfer stream packet based on the at least oneIPDG packet generated according to the type of the at least one IPDGpacket and the IPDG packet regarding the signaling information of the atleast one IP packet; and transmitting the at least one transfer streampacket.
 2. The method of claim 1, wherein the characteristics of theIPDC service comprise at least one of a bandwidth assigned to providethe IPDC service, a coverage range of the IPDC service, and a broadcastreceiver type to which the IPDC service is provided.
 3. The method ofclaim 1, wherein, in the determining of the type of the at least oneIPDG packet to be generated by encapsulating the at least one IP packetbased on the characteristics of the IPDC service, the type of the atleast one IPDG packet comprises at least one of: a normal type fortransmitting a normal type Internet Protocol (IP) packet having an IPheader, a User Datagram Protocol (UDP) header, and a Real-time TransportProtocol (RTP) header; a Digital Audio Broadcasting—Real-time TransportProtocol (DAB-RTP) type for transmitting RTP data and informationrequired to process at least one RTP packet; a compressed RTP type fortransmitting information required to process the RTP data, the at leastone RTP packet, and a compressed IP header, a compressed UDP header, anda compressed RTP header; and a compressed IP type for transmitting theRTP data and the compressed the IP, the UDP, and the RTP headers.
 4. Themethod of claim 3, wherein the information required to process the atleast one RTP packet comprises a time stamp and a sequence number whichare in an RTP header of an original IP packet.
 5. The method of claim 3,wherein, if the type of the at least one IPDG packet is the compressedRTP type, the at least one IPDG packet comprises a pointer field forrepresenting a location of an RTP payload to allow a broadcast receiver,which is not capable of processing the IP packet, to access the RTPpayload.
 6. The method of claim 3, wherein, in the determining of thetype of the at least one IPDG packet, if the IPDC service can beprovided with only data of an RTP payload, the type of the at least oneIPDG packet is determined as the DAB-RTP type; if the IPDC servicerequires header information of the at least one IP packet, the type ofthe at least one IPDG packet is determined as the compressed RTP type;and if the IPDC service is provided to a broadcast receiver whichreceives an IPDC service which is capable of processing a header of acompressed IP packet while reducing an available bandwidth, compared tothe normal type, the DAB-RTP type, or the compressed RTP type, the typeof the at least one IPDG packet is determined as the compressed IP type.7. The method of claim 1, wherein the at least one transfer streampacket comprises at least one IPDG packet and has a size of 188 bytes.8. The method of claim 1, wherein the generating of the at least onetransfer stream packet comprises: if the at least one IPDG packet whichis transmitted through the at least one transfer stream packet is anormal type, assigning a same service identifier to each of the at leastone IPDG packet; and if the at least one IPDG packet which istransmitted through the at least one transfer stream packet is not thenormal type, assigning a separate service identifier to each of the atleast one IPDG packet.
 9. The method of claim 1, wherein, in thegenerating of the at least one transfer stream packet, if one IPDGpacket is divided into a plurality of transfer stream packets, a headerof each transfer stream packet comprises a pointer field indicating alocation of a next IPDG packet or a location of a header of a transferstream packet for the next IPDG packet, thereby indicating that an IPDGpacket transmitted through each transfer stream packet corresponds towhich segment of the IPDG packet.
 10. The method of claim 1, wherein, inthe generating of the at least one transfer stream packet, if the atleast one IPDG packet is divided into a plurality of transfer streampackets, and if a same service identifier is assigned to each of the atleast one IPDG packet if a transfer stream packet transmitting a finalsegment of the at least one IPDG packet is generated, a next IPDG packetis successively included in the transfer stream packet.
 11. The methodof claim 1, wherein, in the generating of the at least one transferstream packet, if the one IPDG packet is divided into a plurality oftransfer stream packets, and if a separate service identifier isassigned to each of the at least one IPDG packet if a transfer streampacket transmitting a final segment of the one IPDG packet is generated,the transfer stream packet comprises an IPDG packet to which a newservice identifier is assigned and which follows the final segment ofthe one IPDG packet.
 12. The method of claim 1, wherein, in thegenerating of the at least one transfer stream packet, if the one IPDGpacket is divided into a plurality of transfer stream packets, and if atransfer stream packet transmitting a final segment of the one IPDGpacket is generated such that no different IPDG packet is included inthe transfer stream packet, stuffing data is included in the transferstream packet, following the final segment of the one IPDG packet. 13.An Internet Protocol Datacasting (IPDC) service providing apparatuscomprising: a data input unit which generates at least one InternetProtocol (IP) packet and signaling information of the at least one IPpacket; a packet generation control unit which determines a type of atleast one Internet Protocol Data Group (IPDG) packet to be generated byencapsulating the at least one IP packet, based on characteristics ofthe IPDC service; an IPDG packet generation unit which generates the atleast one IPDG packet according to the type of the at least one IPDGpacket, and generates an IPDG packet regarding the signaling informationof the at least one IP packet; a transfer stream packet generation unitwhich generates at least one transfer stream packet based on the atleast one IPDG packet generated according to the type of the at leastone IPDG packet and the IPDG packet regarding the signaling informationof the at least one IP packet; and a transfer unit which transmits theat least one transfer stream packet.
 14. The apparatus of claim 13,wherein the characteristics of the IPDC service comprises at least oneof a bandwidth assigned to provide the IPDC service, a coverage range ofthe IPDC service, and a broadcast receiver type to which the IPDCservice is provided.
 15. The apparatus of claim 13, wherein the packetgeneration control unit determines the type of the at least one IPDGpacket as at least one of: a normal type for transmitting a normal typeIP packet having an IP header, a User Datagram Protocol (UDP), and aReal-time Transport Protocol (RTP) header; a Digital AudioBroadcasting—Real-time Transport Protocol (DAB-RTP) type fortransmitting RTP data and information required to process at least oneRTP packet; a compressed RTP type for transmitting information requiredto process the at least one RTP packet, a compressed IP header, acompressed UDP header, and a compressed RTP header, and the RTP data;and a compressed IP type for transmitting the RTP data and thecompressed the IP, the UDP, and the RTP headers.
 16. The apparatus ofclaim 15, wherein the information required to process the at least oneRTP packet comprises a time stamp and a sequence number which are in anRTP header of an original IP packet.
 17. The apparatus of claim 15,wherein, if the type of the at least one IPDG packet is the compressedRTP type, the at least one IPDG packet comprises a pointer field forrepresenting a location of an RTP payload to allow a broadcast receiverwhich is not capable of processing the at least one IP packet to accessthe RTP payload.
 18. The apparatus of claim 15, wherein the packetgeneration control unit, determines the type of the at least one IPDGpacket as the DAB-RTP type if the IPDC service can be provided with onlydata of an RTP payload, determines the type of the at least one IPDGpacket as the compressed RTP type if the IPDC service requires headerinformation of the at least one IP packet, and determines the type ofthe at least one IPDG packet as the compressed IP type, if the IPDCservice is provided to a broadcast receiver which receives an IPDCservice which is capable of processing a header of a compressed IPpacket while reducing an available bandwidth, compared to the normaltype, the DAB-RTP type, or the compressed RTP type.
 19. The apparatus ofclaim 13, wherein the transfer stream packet comprises at least one IPDGpacket and has a size of 188 bytes.
 20. The apparatus of claim 13,wherein the transfer stream packet generation unit, assigns a sameservice identifier to each of the at least one IPDG packet, if the atleast one IPDG packet which is transmitted through the at least onetransfer stream packet is a normal type, and assigns a separate serviceidentifier to each of the at least one IPDG packet, if the at least oneIPDG packet which is transmitted through the at least one transferstream packet is not the normal type.
 21. The apparatus of claim 13,wherein, if the at least one IPDG packet is divided into a plurality oftransfer stream packets, the transfer stream packet generation unitindicates that an IPDG packet transmitted through each transfer streampacket corresponds to which segment of the IPDG packet, using a pointerfield which is included in a header of each transfer stream packet andindicates a location of a next IPDG packet or a location of a header ofa transfer stream packet for the next IPDG packet.
 22. The apparatus ofclaim 13, wherein, if the one IPDG packet is divided into a plurality oftransfer stream packets, and if a same service identifier is assigned toeach of the at least one IPDG packet if a transfer stream packettransmitting a final segment of the one IPDG packet is generated, thetransfer stream packet generation unit generates the transfer streampacket such that a next IPDG packet is successively included in thetransfer stream packet.
 23. The apparatus of claim 13, wherein, if theone IPDG packet is divided into a plurality of transfer stream packets,and if a separate service identifier is assigned to each of the at leastone IPDG packet if a transfer stream packet transmitting a final segmentof the one IPDG packet is generated, the transfer stream packetgeneration unit generates the transfer stream packet such that thetransfer stream packet comprises an IPDG packet to which a new serviceidentifier is assigned and which follows the final segment of the oneIPDG packet.
 24. The apparatus of claim 13, wherein, if one IPDG packetis divided into a plurality of transfer stream packets, and if atransfer stream packet transmitting a final segment of the one IPDGpacket is generated such that no different IPDG packet is included inthe transfer stream packet, the transfer steam packet generation unitgenerates the transfer stream packet, such that stuffing data isincluded in the transfer stream packet, following the final segment ofthe one IPDG packet.
 25. An Internet Protocol Datacasting (IPDC) serviceprocessing method comprising: receiving at least one transfer streampacket including at least one Internet Protocol Data Group (IPDG) packetgenerated by encapsulating at least one Internet Protocol (IP) packet;processing the at least one transfer stream packet; extracting the atleast one IP packet or signaling information of the at least one IPpacket, from the at least one IPDG packet, using type informationindicating an IPDG packet type which is included in a header of the atleast one IPDG packet and determined based on characteristics of theIPDC service; and processing the at least one IP packet and thesignaling information of the at least one IP packet.
 26. The method ofclaim 25, wherein the characteristics of the IPDC service comprises atleast one of a bandwidth assigned to provide the IPDC service, acoverage range of the IPDC service, and a broadcast receiver type towhich the IPDC service is provided.
 27. The method of claim 25, whereinan IPDG packet type to which the at least one IP packet belongscomprises one of: a normal type for transmitting at least one normaltype IP packet having an IP header, a User Datagram Protocol (UDP)header, and an Real-time Transport Protocol (RTP) header; a DigitalAudio Broadcasting—Real-time Transport Protocol (DAB-RTP) type fortransmitting RTP data and information required to process at least oneRTP packet; a compressed RTP type for transmitting information requiredto process the at least one RTP packet, a compressed IP header, acompressed UDP header, and a compressed RTP header, and the RTP data;and a compressed IP type for transmitting the RTP data and thecompressed IP, the UDP, and the RTP headers.
 28. The method of claim 27,wherein the information required to process the at least one RTP packetcomprises a time stamp and a sequence number which are in an RTP headerof an original IP packet.
 29. The method of claim 25, wherein, if thetype of the at least one IPDG packet is a Digital AudioBroadcast-Real-time Transport Protocol (DAB-RTP) type for transmittinginformation required to process at least one RTP packet and RTP data,the processing of the at least one IP packet comprises processing RTPdata included in a payload of the at least one IPDG packet usinginformation required to process the at least one RTP packet.
 30. Themethod of claim 25, wherein the processing of the at least one IP packetcomprises: if the type of the at least one IPDG packet including the atleast one IP packet is a compressed Real-time Transport Protocol (RTP)type for transmitting information required to process at least one RTPpacket, a compressed IP header, a compressed User Datagram Protocol(UDP) header, and a compressed RTP header, and RTP data, and if afunction for restoring the compressed IP, the UDP, and the RTP headersis provided, restoring the compressed IP, the UDP, and the RTP headersto process the RTP data, and if no function for restoring the compressedIP, the UDP, and the RTP headers is provided, processing the RTP dataincluded in the payload of the at least one IPDG packet usinginformation required to process the at least one RTP packet.
 31. Themethod of claim 25, wherein the processing of the at least one IP packetcomprises restoring a compressed IP header, a compressed User DatagramProtocol (UDP) header, and a compressed Real-time Transport Protocol(RTP) header, and processing RTP data, if the type of the at least oneIPDG packet including the at least one IP packet is a compressed IP typefor transmitting the compressed IP, the UDP, and the RTP headers and theRTP data.
 32. The method of claim 25, wherein the processing of thesignaling information of the at least one IP packet comprises:processing primary signaling information for a primary service of theIPDC service; and processing complete signaling information for theremaining services of the IPDC service.
 33. The method of claim 25,wherein the processing of the at least one IP packet comprisesprocessing at least one IP packet included in at least one IPDG packetin which a same service identifier SID for identifying an IPDC serviceincluded in a header of at least one transfer stream packet is included,and providing the IPDC service.
 34. An Internet Protocol Datacasting(IPDC) service processing apparatus comprising: a receiver whichreceives at least one transfer stream packet including at least oneInternet Protocol Data Group (IPDG) packet generated by encapsulating atleast one IP packet; a transfer stream packet processing unit whichprocesses the at least one transfer stream packet and generates the atleast one IPDG packet; an IPDG packet processing unit which extracts theat least one Internet Protocol (IP) packet or signaling information ofthe at least one IP packet, from the at least one IPDG packet, usingtype information indicating an IPDG packet type determined based oncharacteristics of an IPDC service included in a header of the at leastone IPDG packet; and a data processing unit which processes the at leastone IP packet or the signaling information of the at least one IPpacket.
 35. The apparatus of claim 34, wherein the characteristics ofthe IPDC service comprises at least one of a bandwidth assigned toprovide the IPDC service, a coverage range of the IPDC service, and abroadcast receiver type to which the IPDC service is provided.
 36. Theapparatus of claim 34, wherein the type of the at least one IPDG packetto which the at least one IP packet belongs comprises at least one typeof: a normal type for transmitting at least one normal type IP packethaving an IP header, a User Datagram Protocol (UDP) header, and anReal-time Transport Protocol (RTP) header; a Digital AudioBroadcasting—Real-time Transport Protocol (DAB-RTP) type fortransmitting RTP data and information required to process at least oneRTP packet; a compressed RTP type for transmitting the informationrequired to process the at least one RTP packet, a compressed IP header,a compressed UDP header, and a compressed RTP header, and the RTP data;and a compressed IP type for transmitting the RTP data and thecompressed IP, the UDP, and the RTP headers.
 37. The apparatus of claim36, wherein the information required to process the at least one RTPpacket comprises a time stamp and a sequence number which are in an RTPheader of an original IP packet.
 38. The apparatus of claim 34, wherein,if the type of the at least one IPDG packet including the at least oneIP packet is a Digital Audio Broadcast-Real-time Transport Protocol(DAB-RTP) type for transmitting RTP data and information required toprocess at least one RTP packet, the data processing unit processes anRTP payload of the at least one IPDG packet using the informationrequired to process the at least one RTP packet.
 39. The apparatus ofclaim 34, wherein, if the type of the at least one IPDG packet includingthe at least one IP packet is a compressed Real-time Transport Protocol(RTP) type for transmitting information required to process at least oneRTP packet, a compressed IP header, a compressed User Datagram Protocol(UDP) header, and a compressed RTP header, and RTP data, the dataprocessing unit, restores the compressed IP, the UDP, and the RTPheaders to process the RTP data, if a function for restoring thecompressed IP, the UDP, and the RTP headers is provided, and processesan RTP payload included in a payload of the at least one IPDG packetusing the information required to process the at least one RTP packet,if no function for restoring the compressed IP, the UDP, and the RTPheaders is provided.
 40. The apparatus of claim 34, wherein, if the typeof the at least one IPDG packet including the at least one IP packet isa compressed IP type for transmitting Real-time Transport Protocol (RTP)data and a compressed IP header, a compressed User Datagram Protocol(UDP) header, and a compressed RTP header, the data processing unitrestores the compressed IP, the UDP, and the RTP headers to process aRTP payload of the at least one IPDG packet.
 41. The apparatus of claim34, wherein the data processing unit processes primary signalinginformation for a primary service of the IPDC service, and processescomplete signaling information for the remaining IPDC services of theIPDC service, if the signaling information of the at least one IP packetis processed.
 42. The apparatus of claim 34, wherein the data processingunit processes at least one IP packet included in at least one IPDGpacket in which a same service identifier SID for identifying an IPDCservice included in a header of at least one transfer stream packet isincluded, and provides the IPDC service.
 43. A computer-readablerecording medium having embodied thereon a program for executing anInternet Protocol Datacasting (IPDC) service providing method, themethod comprising: generating at least one Internet Protocol (IP) packetand signaling information of the at least one IP packet; determining atype of at least one Internet Protocol Data Group (IPDG) packet to begenerated by encapsulating the at least one IP packet, based oncharacteristics of the IPDC service; generating the at least one IPDGpacket according to the type of the at least one IPDG packet; generatingan IPDG packet regarding the signaling information of the at least oneIP packet; generating at least one transfer stream packet based on theat least one IPDG packet generated according to the type of the at leastone IPDG packet and the IPDG packet regarding the signaling informationof the at least one IP packet; and transmitting the at least onetransfer stream packet.
 44. A computer-readable recording medium havingembodied thereon a program for executing an Internet ProtocolDatacasting (IPDC) service processing method, the method comprising:receiving at least one transfer stream packet including at least oneInternet Protocol Data Group (IPDG) packet generated by encapsulating atleast one IP packet; processing the at least one transfer stream packet;extracting the at least one IP packet or signaling information of the atleast one IP packet, from the at least one IPDG packet, using typeinformation indicating an IPDG packet type included in a header of theat least one IPDG packet and determined based on characteristics of theIPDC service; and processing the at least one IP packet and thesignaling information of the at least one IP packet.